Printer devices of the present invention include a print head, e.g. an ink jet, impact, or thermal print head, pivotally connected to a carriage that moves back and forth across the strip to be printed, along a rectilinear guide secured to a body. The print head is held pressed against a platen by a spring disposed between the carriage and the head, said platen facing the head and being secured to the body. After a line has been printed, the strip, e.g. a strip of paper in the form of a roll that is paid out as printing takes place, is itself displaced perpendicularly to the guide between the print head and the platen by wheels pivotally mounted on the body. When the roll of strip material contained in the device has been used up, it is necessary to install another and to ready the device by inserting the end of the strip inbetween the wheels and between the platen and the print head. In such a device, putting the strip into place in this way can be difficult, and wrong insertion leads to the strip jamming.
To remedy those drawbacks, document WO 96/05062 discloses a printer device comprising a body on which a cover carrying the platen and the wheels is mounted to pivot between a closed position in which the head bears against the platen, and an open position enabling a blank strip to be put into place. After the cover has been opened, it is possible to insert a new roll of strip material, and then the cover is closed while the free end of the strip is held manually so as to be engaged between the platen and the head once the cover is in its closed position.
Such a device makes it easier to install the strip, however while the cover is being moved between its two positions, bumping and rubbing take place between the platen and the print head which is urged into an inclined position by the spring. Such repeated bumping and friction can lead to the print head being damaged or can give rise to slack between the various elements of the device, thus leading to printing of lower quality.